With the development of technology, portable terminals, for example, PDAs, PMPs, navigation systems, and laptop computers provide DMB, wireless Internet access, near field communication functions as well as telephone communication, video/audio playback, map service functions. Therefore, a portable terminal includes a plurality of antennas for wireless communication, for example, wireless Internet access and Bluetooth communication.
Furthermore, there is a recent trend that near field communication (NFC)-based functions, such as information exchange between devices, payment, ticketing, and browsing are mounted in portable terminals. To this end, portable terminals are equipped with an antenna module (i.e. NFC antenna module) for a portable terminal that is used for near field communication. The NFC antenna module is one type of electronic tag (RFID) and is a contactless short range communication module that uses a frequency band of about 13.56 Hz and transmits data to a device at a short distance, 10 cm. The NFC is widely used in various fields, for example, transmission of production information and travel information for visitors in supermarkets or general shops, transmission of traffic information, and transmission of information in gateway control devices, as well as being used for payment for products.
NFC antenna modules are planar and mounted on battery packs or battery covers. That is, as illustrated in FIG. 1, a conventional NFC antenna module includes a shielding sheet 24 (for example, a metal plate such as a ferrite sheet) stacked on the top surface of a battery 22 of a portable terminal 10 and a radial pattern 26 stacked on the shielding sheet 24. The conventional NFC antenna module is generally mounted inside the battery pack 20 of the portable terminal 10. Alternatively, as illustrated in FIG. 2, the NFC antenna module may further include a radial patch 28 that is distanced from the radial pattern 26 and disposed inside the radial pattern 26.
In addition, recently a technology which wirelessly charges a battery of a portable terminal, without using an adaptor for charging, has become applied to portable terminals to enhance user-friendliness. That is, a wireless charging antenna is installed on a battery cover or a battery pack of a portable terminal.
In this case, as illustrated in FIG. 3, when a wireless charging antenna 40 may be installed inside an NFC antenna module 30, a power supply portion of the wireless charging antenna 40 that has a coil form is connected to a power supply terminal of the NFC antenna module 40 through solder medium. To this end, the power supply portion of the wireless charging antenna 40 is pulled out to be exposed to an outside (i.e., the power supply portion of the wireless charging antenna 40 is made to extend over or under the NFC antenna module 30 so as to be connected to the power supply terminal). In this process, a portion of the power supply portion partially overlaps the coil of an antenna portion, causing a height difference H between the NFC antenna module 30 and the wireless charging antenna 40 as illustrated in FIG. 4.
The height difference H between the NFC antenna module and the wireless charging antenna causes a problem of increasing the thickness of a component (for example, battery pack, housing of a portable terminal, etc.) in which the antenna module is mounted.